From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756615Ab3CYBRl (ORCPT ); Sun, 24 Mar 2013 21:17:41 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34173 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756438Ab3CYBQn (ORCPT ); Sun, 24 Mar 2013 21:16:43 -0400 Message-Id: <20130325010526.510354269@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 25 Mar 2013 01:05:46 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, Larry Finger , Jussi Kivilinna , "John W. Linville" Subject: [ 022/104] rtlwifi: rtl8192cu: Fix schedule while atomic bug splat Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In-Reply-To: <20130325010524.240972766@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:f137:78a:b654:affb X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Larry Finger commit 664899786cb49cb52f620e06ac19c0be524a7cfa upstream. When run at debug 3 or higher, rtl8192cu reports a BUG as follows: BUG: scheduling while atomic: kworker/u:0/5281/0x00000002 INFO: lockdep is turned off. Modules linked in: rtl8192cu rtl8192c_common rtlwifi fuse af_packet bnep bluetooth b43 mac80211 cfg80211 ipv6 snd_hda_codec_conexant kvm_amd k vm snd_hda_intel snd_hda_codec bcma rng_core snd_pcm ssb mmc_core snd_seq snd_timer snd_seq_device snd i2c_nforce2 sr_mod pcmcia forcedeth i2c_core soundcore cdrom sg serio_raw k8temp hwmon joydev ac battery pcmcia_core snd_page_alloc video button wmi autofs4 ext4 mbcache jbd2 crc16 thermal processor scsi_dh_alua scsi_dh_hp_sw scsi_dh_rdac scsi_dh_emc scsi_dh ata_generic pata_acpi pata_amd [last unloaded: rtlwifi] Pid: 5281, comm: kworker/u:0 Tainted: G W 3.8.0-wl+ #119 Call Trace: [] __schedule_bug+0x62/0x70 [] __schedule+0x730/0xa30 [] ? usb_hcd_link_urb_to_ep+0x19/0xa0 [] schedule+0x24/0x70 [] schedule_timeout+0x18c/0x2f0 [] ? wait_for_common+0x40/0x180 [] ? ehci_urb_enqueue+0xf1/0xee0 [] ? trace_hardirqs_on+0xd/0x10 [] wait_for_common+0xe5/0x180 [] ? try_to_wake_up+0x2d0/0x2d0 [] wait_for_completion_timeout+0xe/0x10 [] usb_start_wait_urb+0x8c/0x100 [] usb_control_msg+0xd9/0x130 [] _usb_read_sync+0xcd/0x140 [rtlwifi] [] _usb_read32_sync+0xe/0x10 [rtlwifi] [] rtl92cu_update_hal_rate_table+0x1a5/0x1f0 [rtl8192cu] The cause is a synchronous read from routine rtl92cu_update_hal_rate_table(). The resulting output is not critical, thus the debug statement is deleted. Reported-by: Jussi Kivilinna Signed-off-by: Larry Finger Signed-off-by: John W. Linville [bwh: Backported to 3.2: the deleted code is slightly different] Signed-off-by: Ben Hutchings --- drivers/net/wireless/rtlwifi/rtl8192cu/hw.c | 2 -- 1 file changed, 2 deletions(-) --- a/drivers/net/wireless/rtlwifi/rtl8192cu/hw.c +++ b/drivers/net/wireless/rtlwifi/rtl8192cu/hw.c @@ -2238,8 +2238,6 @@ void rtl92cu_update_hal_rate_table(struc (shortgi_rate << 4) | (shortgi_rate); } rtl_write_dword(rtlpriv, REG_ARFR0 + ratr_index * 4, ratr_value); - RT_TRACE(rtlpriv, COMP_RATR, DBG_DMESG, ("%x\n", rtl_read_dword(rtlpriv, - REG_ARFR0))); } void rtl92cu_update_hal_rate_mask(struct ieee80211_hw *hw, u8 rssi_level)